package jjn.carl.dp;

import java.util.Scanner;

/**
 * @author Jjn
 * @since 2023/8/4 23:52
 */
public class LeetCode70 {
    public int climbStairs(int n) {
        if (n <= 1) {
            return n;
        }
        int[] dp = new int[n + 1];
        dp[1] = 1;
        dp[2] = 2;
        for (int i = 3; i <= n; i++) {
            dp[i] = dp[i - 1] + dp[i - 2];
        }
        return dp[n];
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            int n = scanner.nextInt();
            System.out.println(new LeetCode70().climbStairs(n));
        }
    }
}
